A wide variety of building materials and finishing materials in static structures, such as homes, commercial buildings and schools are commonly coated and/or impregnated with compositions designed to impart the ability to reduce the concentration of VOC's. Porous building materials, such as ceiling tile substrates prepared from a slurry of fibers, fillers and binders, are exemplary of such materials.
In the following description, formaldehyde is used for illustrative purposes of a VOC which includes other aldehydes. The International Agency on Cancer Research has classified formaldehyde as a known carcinogen. Exposure to high concentrations of formaldehyde, as well as chronic exposure at lower concentrations, can cause watery eyes, burning sensations in the eyes and throat, difficulty in breathing and other symptoms. It is also common for people to develop sensitivity to formaldehyde, as well as other aldehydes, resulting in skin rashes, hives and the like. People are often exposed to formaldehyde in the interior building environment through its use in construction materials, wood products, textiles, home or office furnishings, paper, cosmetics, cigarette smoke, pharmaceuticals and indoor cleaning products. Formaldehyde levels are particularly high in new construction due to high emissions from new construction materials. Thus, there has been a long felt need to reduce or eliminate formaldehyde concentrations in the interior building environment.
Conventional attempts include but are not limited to reaction with amines and other formaldehyde reactive materials. Furthermore, there have been attempts, specifically in the art of ceiling tile and gypsum wallboard substrates, to include formaldehyde reducing additives in the overall formulation of the slurry from which the board is made as well as in the coatings applied thereto. Although some reduction of formaldehyde from the air has been achieved via these reactive systems, the formaldehyde reduction is short lived. As a result, a more effective formaldehyde reducer, and in particular, one having a long efficacy of substantial formaldehyde reduction is needed.